外文翻译--研究一个离心泵内的震动压力—利用数字表示的方法来支持工业实验.doc

英文文献INVESTIGATIONINTOPRESSUREPULSATIONSINACENTRIFUGALPUMPUSINGNUMERICALMETHODSSUPPORTEDBYINDUSTRIALTESTSRSPENCEANDJAMARALTEIXEIRAABSTRACTTHEOPERATIONOFCENTRIFUGALPUMPSCANGENERATEINSTABILITIESANDPRESSUREPULSATIONSTHATMAYBEDETRIMENTALTOTHEINTEGRITYANDPERFORMANCEOFTHEPUMPINTHEPRESENTSTUDYANUMERICALINVESTIGATIONOFTHETIMEVARIATIONOFPRESSUREWITHINACOMPLETEPUMPWASUNDERTAKENARANGEOFPARAMETERSANDTHREEFLOWRATESWEREINVESTIGATEDANDTHEPULSATIONSWEREEXTRACTEDAT15DIFFERENTLOCATIONSCOVERINGIMPORTANTPUMPLOCATIONSEXPERIENCINGTHELARGESTPULSATIONLEVELSITWASALSONOTETHATMONITORINGPULSATIONSATTHETOPDEADCENTREOFTHEPUMPVOLUTECASINGWOULDPROVIDEABETTERINDICATIONOFINTERNALPUMPPULSATIONSTHANMONITORINGATTHEDISCHARGE1、INTRODUCTIONCENTRIFUGALPUMPSHAVEBEENDEVELOPEDANDREFINEDOVERMANYYEARSINPRACTICETHEDESIGNOFBOTHTHEIMPELLERANDVOLUTEARECOMPLEX,WITHNUMEROUSGEOMETRICALPARAMETERSBEINGREQUIREDTOIDENTIFYADESIGNTHATWILLFORMAHYDRAULICALLYEFFICIENTPUMPEVENWITHTRIEDDESIGNSITISWELLKNOWNTHATTHEOPERATIONOFROTODYNAMICPUMPCANRESULTINTHEGENERATIONOFTHEDESIGNPROCESSUSED；THEFINALDECISIONREGARDINGTHESUITABILITYOFANYSIGNIFICANTLYNEWPUMPDESIGNISUSUALLYMADEFOLLOWINGPHYSICALTESTINGTHESETESTSAREOFTENEXPENSIVEINTERMOFTIMEANDRESOURCES,FOREXAMPLEDUETOTHEMANUFACTURINGOFPATTERNEQUIPMENT,THEPROTOTYPEPUMPITSELFASWELLASTHEASSEMBLYANDTHEUSEOFTESTFACILITIESGRADUALLY,PUMPMANUFACTURERSARETURNINGTOCOMPUTATIONALTECHNIQUESTOSTUDYDESIGNFEATURESTYPICALLYTHESEINVESTIGATIONSARECONDUCTEDWITHAVIEWTOREDUCING,ORELIMINATINGTHENUMBEROFTESTSCONDUCTEDANDTOHIGHLIGHTANYUNDESIRABLEDESIGNCHARACTERISTICSATANEARLYSTAGEALTHOUGHCOMMERCIALCFDPACKAGESHAVEBEENUSEDTOPREDICTTIMEDEPENDENTPRESSUREPULSATIONS,COMPUTATIONALFACILITIESSEEMTOHAVELIMITEDMOSTOFTHATWORKTOSIMULATINGTHEVOLUTEANDIMPELLERINTERACTIONSONLY,WITHOUTTHESUCTIONINLETBRANCHANDLEAKAGEFLOWPATHSBEINGCONSIDEREDTHECURRENTWORKAIMSTOIMPROVETHEQUALITYANDSCOPEOFPREVIOUSWORKRELATEDTOPRESSUREPULSATIONSBYPERFORMINGSIMULATIONSINVOLVINGTHECOMPLETEHYDRAULICPUMPGEOMETRYTHENUMERICALMODELINCORPORATESALLOFTHEMAJORFLOWPATHSINAPUMPENCOMPASSINGTHESUCTIONINLET,IMPELLER,LEAKAGEPATHWAYSANDTHEVOLUTECASINGTHEWORKFOCUSESONAREDUCEDSCALEVERSIONOFAHIGHENERGYIMPELLERINADOUBLEENTRY,SINGLESTAGEPUMPARRANGEMENTTHEUNDERSTANDINGOFPRESSUREPULSATIONSBYPUMPMANUFACTURERSSEEMSSURPRISINGLYLIMITEDNOOFFICIALSTANDARDSEXISTFORSAFELEVELSOFPRESSUREPULSATIONSINPUMPS；THEONLYINDUSTRYADOPTEDGUIDELINEISAGUARANTEEOFLESSTHAN3VARIATIONINTHEPUMPOUTLETPRESSUREYET,ITISNOTKNOWNWHETHERALIMITATIONOF3VARIATIONINTHEDISCHARGECORRESPONDSTOASAFELIMITATOTHERLOCATIONSWITHINAPUMPTHEREFOREADETAILEDASSESSMENTOFPREESUREPULSATIONSINBOTHTHEIMPELLERANDVOLUTEHASBEENPERFORMEDTOGUARANTEEFOROTHERCRITICALPARTSOFTHEPUMPTHEANALYSISCOVERSTHREEFLOWRATESOVERAFLOWRANGEEXTENDINGFROMTHEPUMPDUTYCONDITION100OQNTOACOMMONPUMPMINIMUMOPERATINGPOINTOF25OFTHEDUTYCONDITION025OQNTHEANALYSESPRESENTEDHEREAREPARTOFALARGEPARAMETRICSTUDYINVESTIGATINGTHEEFFECTOFINTERNALGEOMETRYONPRESSUREPULSATIONSWITHINTHEPUMPDUETOTHECONSTRAINSINVOLVEDINSUCHALARGESTUDY,ONEADDITIONALAIMOFTHISWORKWASTOSHOWTHATAREASONABLEESTIMATEOFPRESSUREPULSATIONSANDTRENDSINPRESSUREPULSATIONSCANBEACHIEVED,FORDIFFERINGPUMPGEOMETRIES,INAREASONABLETIMEFRAMEBYNUMERICALMEANS2、EXPERIMENTALINVESTIGATIONSOMEEXPERIMENTALRESULTSWEREAVAILABLETOONEOFTHEAUTHORSFROMINDUSTRIALTESTSPERFORMEDTOEXAMINEPRESSUREPULSATIONSINAREDUCEDSCALECONTRACTPUMPTHISEXPERIMENTALWORKPERFORMEDANUMBEROFYEARSBEFORETHENUMERICALANALYSESTHEPUMPRECEIVEDFLUIDFROMACLOSEDSYSTEM,SUCHTHATTHEPUMPWASSITUATEDWITHABEND35DIAMETERSUPSTREAMANDASECONDBEND4DIAMETERSDOWNSTREAMDIRECTLYFOLLOWINGTHEUPSTREAMBEND,FLOWSTRAIGHTENERSWEREFITTENINORDERTOREDUCETHEFLOWEFFECTSCAUSEDBYTHEBENDONTHEINFLOWTOTHEPUMPTENZTYPEKISTLERPRESSURETAPPINGSWEREMOUNTEDONTHEPUMPPRESSURETAPPINGSWEREUSEDTOCOLLECTDATAATVARIOUSSTATIONARYLOCATIONSAROUNDTHEPUMPHOLESWEREDRILLEDATSPECIFICLOCATIONSAROUNDTHEPUMPANDTUBESWEREUSEDTOCONNECTTHEPRESSURETRANSDUCERSTOEACHLOCATIONTHEPATHDISTANCEFROMTHETAPPINGPOINTTOTHETRANSDUCERWASKEPTASSHORTASPOSSIBLE1015OMMTOENSURETHATANYRESONANTFREQUENCIESCAUSEDBYTHEPATHDISTANCEAREABOVETHEMEASUREDRANGEONEZTYPEENTRANPRESSURETRANSDUCERWASUTILIZEDINTHEEXPERIMENTALTESTSTHISTRANSDUCERWASMOUNTEDINTHEIMPELLERSHROUD15OMMBEHINDTHESUCTIONFACEOFANIMPELLERBLADETHEELECTRICALSIGNALSFROMTHETRANSDUCERSWERETRANSFERREDFROMTHEROTATINGELEMENTTHESTATIONARYDATARECORDERVIAASLIPRINGARRANGEMENTATTHENONDRIVEENDOFTHEPUMPTHETESTRINGWASRUNATANINITIALSPEEDOF1400RPMOVERTHEFLOWRANGE25125OFDUTYWITH5MINTAPERECORDINGSOFTHETRANSDUCERSBEINGTAKENATEACH25FLOWINCREMENTTHE100OQNDUTYCONDITIONEQUATEDTOAFLOWRATEOF500OM3/HANDANOMINALHEADOF338OMFORTHEINLINEIMPELLERWHENTHEPUMPWASRUNAT1400RPMTHEFLOWCHANGEWASACHIEVEDBYADJUSTINGAFLOWVALVEASSLOWLYANDASSMOOTHLYASPOSSIBLEARANGEOFTESTSWASPERFORMEDFORANUMBEROFPUMPGEOMETRICALARRANGEMENTS,HOWEVERONLYTWOAREOFPARTICULARINTERESTHERETERMEDAANDBASDETAILEDABOVEATIMEHISTORYOFTHEPRESSUREVARIATIONATEACHOFTHEABOVELOCATIONSISRECORDEDASPECTRALANALYSISWASTHENCONDUCTEDONTHISDATAWITHTHEPRESSUREPULSATIONSBEINGOUTPUTASTHEROOTMEANSQUARERMSPRESSUREPULSATIONDUETOTHETIMECONSTRA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